21636430401 has 16 divisors (see below), whose sum is σ = 29615065344. Its totient is φ = 14044222464.

The previous prime is 21636430397. The next prime is 21636430423. The reversal of 21636430401 is 10403463612.

It is not a de Polignac number, because 21636430401 - 2² = 21636430397 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21636430001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 370326 + ... + 424751.

It is an arithmetic number, because the mean of its divisors is an integer number (1850941584).

Almost surely, 2^21636430401 is an apocalyptic number.

It is an amenable number.

21636430401 is a deficient number, since it is larger than the sum of its proper divisors (7978634943).

21636430401 is a wasteful number, since it uses less digits than its factorization.

21636430401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 795320.

The product of its (nonzero) digits is 10368, while the sum is 30.

The spelling of 21636430401 in words is "twenty-one billion, six hundred thirty-six million, four hundred thirty thousand, four hundred one".